There is a need for low cost, reliable packages with a standard footprint for interconnecting two or more semiconductor chips. Such packages must be able to be modified easily for specialized applications having limited projected sales as well as for mass market sales. Thus the packaging process must be able to interconnect two or more semiconductor chips selected from a wide range of semiconductor chips available now or in the future.
The generally preferred method of making vertically stacked multiple die package uses wire bonds to connect a leadframe to the die. However, as compared to flip chip, wire bonds are not considered to be as good as flip-chip attachment of die to a leadframe in both electrical and thermal performances. In addition, the flip-chip attachment on a pre-molded leadframe is also a economical method to package a semiconductor die.